Found in a 90s Popular Electronics, this circuit uses common components. The power transistors can be current equivalents of the TIP or BD series.
In the figure we show our first circuit that consists of a simple touch switch capable of driving a...
This circuit was found in an 80's Electronic Engineering. The power supply must be symmetrical. The...
This metal detector was found in a French magazine Radio Plans from 1977. The phone can be a...